National Oilheat Research Alliance 35
Figure 6-Off cycle
• the thermostatic trap elements
cool and open.
• the F&T trap float valve
closes. Figure 6.
Heat Emitter operation with a
typical two pipe system
Startup - steam approaches the heat emitter
and pushes air out, through a thermostatic trap,
into the return. Figure 7, below.
Figure 7
Steam reaches heat emitter
- Steam pushes into
the heat emitter and rises
to the top, thermostatic
trap allows air to pass into
return. Heat emitter starts
to warm up and condensate
begins to form.
Figure 8, below.
Steady state - Trap closes
when steam reaches it,
heat emitter releases
heat to room. Condensate
builds up in the heat
emitter until it is at least
10° lower than the steam
temperature at which time
the trap opens and allows
condensate to flow into
the return until the thermostatic
element senses
steam temperature again.
Figure 9, below.
Figure 8
Figure 9